A 16-year-old boy who apparently survived unscathed after a five-hour flight
from California to Hawaii stowed away in the nose-wheel compartment of a
passenger jet, left medical and aviation experts perplexed and divided last
night.

A 16-year-old boy, sitting on a stretcher, centre, stowed away in the wheel well of a flight from San Jose to MauiPhoto: Chris Sugidono/The Maui News/AP

A 16-year-old boy who apparently survived unscathed freezing temperatures and a lack of oxygen after a five-hour flight from California to Hawaii stowed away in the wheel well left medical and aviation experts perplexed and divided on Monday night.

While experts questioned how the boy had survived, the FBI said that security camera footage had shown the unnamed teenager scaling the perimeter fence at California’s San Jose airport on Sunday morning and walking towards a Hawaiian Airlines Boeing 767 that took off shortly afterwards for Kahului airport on Maui island.

Five hours later airline officials said the boy was found dazed but otherwise unhurt wandering on the tarmac at Kahului, after flying halfway across the pacific at a maximum altitude of 38,000ft where outside temperatures descended as low as minus 80F.

Photographs shown on local media appeared to show the boy sitting upright and alert as he was wheeled into an ambulance at Kahului airport.

Officials said he had run away from home after a row with his parents and arrived on Flight 45 to Hawaii with only the clothes he was wearing and a pocket comb. He was carrying no form of identification but officials said last night that his parents had been informed.

“How he survived, I don't know. It's a miracle,” said Tom Simon, an FBI spokesman in Honolulu who added that the boy’s story appeared to “check out” following examination of the video footage from the Mineta International Airport in San Jose.

“Kid's lucky to be alive,” added Mr Simon, speaking to local media, who said the boy had been unconscious for most of the flight. He had been handed over to child services in Honolulu and had not been charged with any crime.

"Doesn't even remember the flight," Simon said. "It's amazing he survived that. It's just an apparent miracle ... There was no appearance of any special gear of any sort.”

The survival of the boy, who is reported to be from Santa Clara, California, was greeted with incredulity by several of America’s leading aviation analysts.

“Somebody surviving at 35,000 feet for five hours with no supplemental oxygen supply; I just don’t believe it,” said John Nance, one of America’s leading aviation experts told ABC News.

“[This] is one of three things - a hoax, a miracle or we're going to have to rewrite the textbooks if he actually did what he says he did,” he added, “He needs to be studied very carefully by medical science because this is not supposed to be possible.”

Peter Forman, another leading airline analyst, was similarly perplexed. “The odds of a person surviving that long of a flight at that altitude are very remote, actually. I mean, you are talking about altitudes that are well above the altitude of Mount Everest,” he told Hawaii’s KHON radio.

“A lot of people would only have useful consciousness for a minute or two at that altitude. For somebody to survive multiple hours with that lack of oxygen and that cold is just miraculous. I’ve never heard of anything like that before.”

Among the theories is that the lack of oxygen and slow cooling of the body could send the central nervous system into a form of hibernation, not unlike an animal in winter, with latent heat from the nose wheels and hydraulic lines keeping the body from freezing completely.

Five people survived, including a stowaway on a flight from Panama City to Miami in 1986 that reached 39,000ft, with the conditions putting them in a virtual “hibernative” state, the report said.

If confirmed, however, the boy’s escape would still comfortably exceed the parameters of two more recently reported cases of stowaway survival.

In August 2013, a Nigerian teenager survived a 35-minute flight in the landing gear compartment of a domestic flight, with officials crediting the short flight time and relatively low altitude of the flight path with helping him survive.

Similarly, in June 2010 a 20-year-old Romanian man survived temperatures of -41C inside the landing gear of a Boeing 747 on a 97-minute flight from Vienna to Heathrow.

Again, officials explained his survival by the fact that thunderstorms had forced the plane to remain at 25,000ft, just low enough for the man to survive, and far short of its usual 37,000ft cruising altitude.